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@@ -223,21 +272,114 @@ void CIRRecordLowering::fillOutputFields() {
fieldTypes.size() - 1;
// A field without storage must be a bitfield.
assert(!cir::MissingFeatures::bitfields());
+ if (!member.data)
+ setBitFieldInfo(member.fieldDecl, member.offset, fieldTypes.back());
}
assert(!cir::MissingFeatures::cxxSupport());
}
}
+void CIRRecordLowering::accumulateBitFields(
+ RecordDecl::field_iterator field, RecordDecl::field_iterator fieldEnd) {
+ // Run stores the first element of the current run of bitfields. FieldEnd is
+ // used as a special value to note that we don't have a current run. A
+ // bitfield run is a contiguous collection of bitfields that can be stored in
+ // the same storage block. Zero-sized bitfields and bitfields that would
+ // cross an alignment boundary break a run and start a new one.
+ RecordDecl::field_iterator run = fieldEnd;
+ // Tail is the offset of the first bit off the end of the current run. It's
+ // used to determine if the ASTRecordLayout is treating these two bitfields as
+ // contiguous. StartBitOffset is offset of the beginning of the Run.
+ uint64_t startBitOffset, tail = 0;
+ assert(!cir::MissingFeatures::isDiscreteBitFieldABI());
+
+ // Check if OffsetInRecord (the size in bits of the current run) is better
+ // as a single field run. When OffsetInRecord has legal integer width, and
+ // its bitfield offset is naturally aligned, it is better to make the
+ // bitfield a separate storage component so as it can be accessed directly
+ // with lower cost.
+ auto isBetterAsSingleFieldRun = [&](uint64_t offsetInRecord,
+ uint64_t startBitOffset,
+ uint64_t nextTail = 0) {
+ if (!cirGenTypes.getCGModule().getCodeGenOpts().FineGrainedBitfieldAccesses)
+ return false;
+ cirGenTypes.getCGModule().errorNYI(field->getSourceRange(),
+ "NYI FineGrainedBitfield");
+ return true;
+ };
+
+ // The start field is better as a single field run.
+ bool startFieldAsSingleRun = false;
----------------
andykaylor wrote:
Given that `isBetterAsSingleFieldRun` always returns false, this variable can be eliminated and a lot of the code here can be simplified. I suggest removing all that and replacing it with a `MissingFeatures::nonFineGrainedBitfields` assert.
https://github.com/llvm/llvm-project/pull/142041